Essentially, an aerogenerator produces electricity in the following manner: wind rotates the aerogenerator rotor, causing the turning of a generator (a dynamo) which produces electricity.
The main components of the nacelle of an aerogenerator are:                The rotor: constituted by blades which pick up the wind; it is bolted to the main shaft.        The main shaft: between the rotor and the multiplier.        The multiplier: connected between the rotor (at the other end of the main shaft) and the electric generator.        The electric generator.        The crown system: it allows the turning of the nacelle so as to position itself facing the wind according to the signal from the weather vane connected to the control system.        The control system: it controls most of the parts of the aerogenerator; thus, for example, it controls the crown system.        
A wind farm is formed by one or more aerogenerators (up to hundreds of them) and other elements such as a transforming center or electric substation and one or more weather towers. All these elements are usually monitored by a farm monitoring and control system (or remote control) installed in a main computer located in the wind farm itself and connected to the aerogenerators via a local communications network. The application installed in this main computer collects the operation variables from said elements as well as the alarms that occur in them.
Currently, the generated power of a wind farm is put out entirely to the distribution network. Thus, if the utility company authorizes a maximum power supply of X MW, the aerogenerators installation, with regard to number and rated power, shall be adjusted to this limitation. Typically, in base of this power limitation, a study of the site and possible machine locations is carried out so as to determine the optimum number of aerogenerators to be installed in order to obtain the maximum output.